Climate crisis reducing land’s ability to sustain humanity, says IPCC

UN report finds ecosystems never before under such threat and restoration is urgent

The climate crisis is damaging the ability of the land to sustain humanity, with cascading risks becoming increasingly severe as global temperatures rise, according to a landmark UN report compiled by some of the world’s top scientists.

Global heating is increasing droughts, soil erosion and wildfires while diminishing crop yields in the tropics and thawing permafrost near the poles, says the report by the Intergovernmental Panel on Climate Change.

Further heating will lead to unprecedented climate conditions at lower latitudes, with potential growth in hunger, migration and conflict and increased damage to the great northern forests.

The report, approved by the world’s governments, makes clear that humanity faces a stark choice between a vicious or virtuous circle. Continued destruction of forests and huge emissions from cattle and other intensive farming practices will intensify the climate crisis, making the impacts on land still worse.

However, action now to allow soils and forests to regenerate and store carbon, and to cut meat consumption by people and food waste, could play a big role in tackling the climate crisis, the report says.

Such moves would also improve human health, reduce poverty and tackle the huge losses of wildlife across the globe, the IPCC says.

Burning of fossil fuels should end as well to avoid “irreversible loss in land ecosystem services required for food, health and habitable settlements”, the report says.

“This is a perfect storm,” said Dave Reay, a professor at the University of Edinburgh who was an expert reviewer for the IPCC report. “Limited land, an expanding human population, and all wrapped in a suffocating blanket of climate emergency. Earth has never felt smaller, its natural ecosystems never under such direct threat.”

Piers Forster, a professor at the University of Leeds, said: “This important report shows we need to substantially change the way we use our land to limit temperature change below 1.5C. In a nutshell we need less pasture [for livestock] and more trees.” The land-use advice was contained in an IPCC report in October.

Prof Jim Skea, from the IPPC, said the land was already struggling and climate change was adding to its burdens. Almost three-quarters of ice-free land was now directly affected by human activity, the report says.

Poor land use is also behind almost a quarter of the planet’s greenhouse gas emissions – the destruction of forests, huge cattle herds and overuse of chemical fertilisers being key factors.

Emissions relating to fertilisers have risen ninefold since the early 1960s. Rising temperatures are causing deserts to spread, particularly in Asia and Africa, and the Americas and Mediterranean are at risk, the report says.

One of the most stark conclusions in the IPCC report is that soil, upon which humanity is entirely dependent, is being lost more than 100 times faster than it is being formed in ploughed areas; and lost 10 to 20 times faster even on fields that are not tilled.

The report recommends strong action from governments and business, including ending deforestation and enabling new forests to grow, reforming farming subsidies, supporting small farmers and breeding more resilient crops. Many of those solutions, however, would take decades to have an impact, the IPCC says.

Consumers in rich nations could act immediately by reducing their consumption of intensively produced meat and dairy foods – products that have a huge environmental impact.

“There is much more we could do in that space that we are not doing, partly because it is difficult,” said Pete Smith, a professor at the University of Aberdeen and a senior IPCC author. “You wouldn’t want to tell people what to eat, that would go down badly. But you could incentivise.”

The IPCC report suggests “factoring environmental costs into food”. Previous studies have suggested meat taxes, or subsidised fruit and vegetables. Meat production ties up most farmland and cutting consumption could release millions of square kilometres for forestry or bioenergy crops, the report says, as could cutting food waste.

Caterina Brandmayr, of the Green Alliance thinktank, said: “The key message from the IPCC is urgency: we need to act now to plant new forests, restore our ecosystems, and, yes, to eat less meat.”

David Viner, a professor at the University of East Anglia and a senior IPCC author, said: “Land is a vital resource and we have to look after it if we are going to have a sustainable future.”